1. Field of the Invention
The invention relates to a water treatment device, more particularly to a water treatment device which can effectively wash and clean impurities on a filter unit that is contained therein.
2. Description of the Related Art
A conventional water filter device disclosed in Taiwanese Patent No. 221,424 includes a top cover, a bottom cover, and a stack of alternately disposed filter units and stirring members between the top and bottom covers. Each of the filter units has an annular filtering film. The top cover is provided with two side holes for injecting water therethrough. Each of the stirring members includes an inner supporting ring, an outer supporting ring, and a stirring element anchored between the inner and outer supporting rings. The stirring element has a plurality of angularly spaced apart curved ribs. During use, water is injected into the water filter device through the side holes in the top cover to stir the stirring members so that the impurities on the filtering films can be removed by the curved ribs of the stirring elements.
Although the aforesaid conventional water filter device can achieve the effect of cleaning the filtering films, it still has the following shortcomings that need to be overcome. Since the stirring elements are actuated by water injected through the side holes in the top cover, and since water pressure is decreased gradually along a direction from the top cover to the bottom cover, the stirring elements at the lower part of the conventional water filter device may have insufficient stirring speed to clean the adjacent filtering films, and may even stop stirring. Therefore, the cleaning effect of the stirring members of the conventional water filter device is not satisfactory. Furthermore, each stirring element is anchored between the corresponding inner and outer supporting rings. The friction forces between the stirring element and the inner supporting ring and between the stirring element and the outer supporting ring may interfere with stirring activity of the stirring element. Therefore, a relatively high water pressure is required to drive stirring of the stirring elements. Moreover, the filter units in the conventional water filter device are not encapsulated by a container and are instead simply clamped between the top and bottom covers. Therefore, the water spurting due to the stirring of the stirring elements during the cleaning process can moisten the area around the water filter device. Additionally, the water filter device may be contaminated by the dust therearound.